Valve control apparatus



Feb. 15, 1949. M. R. LAING 2,461,608

VALVE CONTROL APPARATUS Feb. 15, 1949.

M. R. LAING VALVE CONTROL APPARATUS Filed Aug. 17, 1942 A 2 Sheets-Sheet2 Patented Feb. 15, 1949 VALVE CONTROL APPARATUS Marvin R. Laing,Minneapolis, Minn., assignor to Minneapolis-Honeywell Regulator Company,-Minneapolis, Minn., a corporation of Delaware Application August 17,1942, serial No. 455,099

scorched and burned paint and creating a fire.

hazard.

Various prior art devices have been devised for curing these troubles ofwhich the slow-opening and step-opening valves are examples. In the caseof the Islovv opening valves, means, such as an auxiliary motor, isemployed and acts as a governor with respect to the main valve motivemeans to delay full opening of the valve. This arrangement is obviouslyan expensive, and therefore, unsatisfactory method of obtaining theresults desired. In the case of the step-opening valves, means isprovided for moving a single valve relatively rapidly to an intermediateposi-l tion Where it remains for a time period and after which itautomatically moves relatively rapidly to the full open position.

The present invention contemplates a valve arrangement in which a pairof electrically operable valves are arranged in parallel. Upon aninitial call for heat, one of the valves is opened to provide a minimumfluid flow. Concurrently with the opening of the first valve, a timeperiod is initiated after which the second valve is opened providingmaximum fluid How. This arrangement, therefore, is Well adaptable as astep-opening valve for overcoming the diiiculties described above. Thearrangement, moreover, may also be used for the same purpose intwo-stage systems in which the rst valve opens in response to a firstpredetermined temperature and the second valve opens in response to asecond predetermined temperature substantially different than'the first.Thus, in two-stage operation, if the thermostat setting is changed in amanner such that a call for second-stage operation occurs simultaneously8 Claims. (Cl. 236-68) of a plurality of valves and a timing means areenergized upon an initial call for heat, thereby opening the first valveto provide a minimum uid flow and initiating a time period after whicha' second valve is opened to provide increased fluid flow. Y

Another object of the invention is the provision, in a two-stage valvecontrol system comprising electrically operable valves, of a timingmeans for delaying the opening of the second stage valve upon a call foroperation thereof during the time period initiated by the timing means.

A further object of the present invention is to provide a pair ofelectrically operable valves arranged in a common valve body and anelectric timing means for delaying the opening of one of the valves, theelectric timing means being mounted on a panel which is secured to thevalve body adjacent to the valve motive means, thereby providing aunitary structure in which the necessary electrical connections betweenthe valves and the timingA means conveniently may be carried by thepanel.

Another object of the invention is the provision, in a unitary valvestructure comprising electrically operable valves and an electric'timingmeans for delaying the opening of one of the valves, of a means forreducing the energization of the timing means after the delayed valvehas been opened, thereby preventing an excessive temperature rise of thestructure.

Still other objects are those implied or inherent in the novelconstruction, combination, and' arrangement of parts hereinafterdescribed and claimed, reference being had to the accompanying drawingsin which:

Figurel 1 is a sectional elevational view of the valve structure asviewed along the lines l--l of Figure 2,

Figure 2 is a plan view of the valve structure as viewed along the lines2-2 of Figure 1, other parts being shown in section to disclose internalstructures,

Figure 3 is a face view of the terminal and timer panel.

Figure 4 is a diagrammatic View of a two-stage valve control systeminwhich the valve structure of Figures 1 and 2 yis employed,

Figure 5 is a diagrammatic view of a twostage Valve control system inwhich a modification of the valve structure of Figures 1 and 2 isemployed, and

Figure 6 is a diagrammatic view of a singlestage valve control system inwhich the valve structure shown in Figures 1 and 2 is employed.

Referring to the drawings, numeral 9 generally designates a valvestructure for controlling the flow of a fluid fuel such as a gas to agas ilred furnace. Although the valve is described in connection with agas furnace, it will be understood that this reference is for purposesof disclosure only and not to be considered in a limiting sense sincethe valve is well adaptable for controlling other fluids as well.

The valve 9 comprises a. valve body I6 having hexagonal projections IIand I2 extending forwardly and rearwardly thereof, respectively.Extending through the projections II and I2 are outlet and inlet portsI3 and I4, respectively, which communicate with the valve chamberinternally of the valve body I and by means of which the valve can beconnected into the gas line communicating with the burner. The valvebody I0 is also provided with plugs I5 which may be removed to provideopenings for connecting the valve body into a gas line communicatingwith the pilot light. The valve chamber is provided with a partition I6which divides the chamber into inlet and outlet chambers I1 and I8,respectively. The partition comprises a horizontal portion which extendsthe full width of the valve body to points forwardly and rearwardly ofthe inlet port I4 and outlet port I3. At the point forwardly of theinlet port I4, the partition extends diagonally downwardly andrearwardly to the corner of the valve body. From the point rearwardly ofthe outlet port I3 the partition extends diagonally upwardly andforwardly to the corner of the valve body. The partition is providedwith a pair of openings which are controlled by a pair of valvesgenerally designated by the numerals I9 and 20, respectively. The valveI9 comprises a stem 2| which carries a valve disk 22. The valve disk 22cooperates with a seat 23 provided in the partition I6, the seatconforming to the shape of the disk to provide a uidtight relation.Similarly, the valve comprises a stem 24 which carries a valve disk 25.As in the case of the valve disk 23, the valve disk 25 cooperates with aseat 26 to provide a fluidtight engagement therewith.

4 sleeve 33 to provide a iluidtight relation in the manner shown.Pressed into the sleeve is a mag netic pin 35. The pins 35 and 35aextend upwardly through holes provided in a casing 36 for housing thesolenoid assemblies 21 and 28. The ends of the pins 35 and 35a arethreaded to receive nuts 31 by means of which the casing 36 is securedto the valve body I0. The casing 36 is formed of magnetic material andextends closely adjacent to the disks 3| and 32 as clearly seen inFigures 1 and 2.

Loosely mounted in the sleeve 33 is a plunger 38. The upper end of theplunger is provided with a counterbore 39 which cooperates with aprojection 40 on the sleeve 34 to guide the plunger in its upwardmovement. The plunger is further provided with a tapered counterbore 4|which is adapted to engage the tapered end of the magnetic pin 35. Theplunger 38 is further counterbored to communicate with a transverse bore42 for the purpose of preventing a dash-pot action as the stop pinengages the tapered bore.

When the coil 39 is energized a main magnetic flux is set up in theplunger 33, disk 32, casing 36, and the disk 3|, by reason of which theplunger moves into engagement with the stop pin 35. In this position, asecond flux path is provided through the plunger 38, stop pin 35, disk32, casing 36, and the disk 3| back to the plunger. Since this iiux paththreads through the sleeve 34,

, the sleeve acts as a shading coil to shade the iiux The valves I9 and20 are actuated by a pair of solenoid assemblies generally designated bythe numerals 21 and 28, respectively. The assemblies 21 and 28 as shownare identical. Accordingly, the assembly 21 only Will be described, andthe same parts will be given the same reference characters. However,whenever it shall be necessary to distinguish the parts of one assemblyfrom the other, the parts of assembly 28 will additionally carry thesubscript a. Furthermore, the assemblies 21 and 28 comprise structureswhich are substantially the same as those described in the patents toGille 2,114,961 and 2,269,- 016. Accordingly, these structures will bedescribed but briefly herein, further reference being had to theforegoing patents for details of construction and operation.

The assembly 21 comprises a nut 29 which is secured and sealed to thevalve body I0 as shown in Figure 1. The nut 29 supports anelectromagnetic coil 30. Disposed above and below the coil 30 areflanged disks 3| and 32 formed of magnetic material. Extending throughthe nut 29, coil 30 and disks 3| and 32 is a sleeve 33 of non-magneticmaterial which is secured to the nut 29 in any suitable iluidtightmanner. The top of the sleeve 33 is closed by a sleeve or shading coil34 of non-magnetic material such as copper, the sleeve 34 being securedand sealed to the therethrough. Accordingly, this arrangement provides ashaded flux for holding the solenoid in positive engagement with thestop pin 35, thereby obviating the chattering which is otherwise presentdue to the cyclical nature of the alternating current.

It is desirable that the valve disks engage and disengage theirrespective seats with a hammer action. For this purpose, a lost motionconnection is provided between each valve stem and its actuatingplunger. To this end, the lower end of the plungerV 38 is hollowed outto threadedly receive a nut 43 through which the stem 2| extends intothe opening provided. The upper end of the stem 2| carries a snap ring44 and a coil spring 45 is inserted between the snap ring and the nut43. Thus, upon upward movement of the plunger, it rst moves relativelyto the stem 2| until it strikes spring 45 to raise the valve disk with ahammer action, the spring 45 serving to cushion the engagement betweenthe plunger and the valve stem 2|. A centering washer 46 is provided forcentering the lower end of the plunger with respect to the sleeve 33 andalso provides a spring tension on the plunger to break its engagementwith the stop pin 35, the washer being retained in place on the nut 29by a snap ring 41. To further prevent the plunger 38 from sticking tothe pin 35 upon deenergization of the coil 30, a conical spring 48 isinserted between the nut 29 and the centering washer 46.

As previously pointed out, when the valve is used in connection with agas fired furnace, it is desirable that only one of the valves open uponan initial call for heat. For this purpose, a timing means later to bedescribed, is provided for delaying the opening of the valve 20 for atime period after the valve I9 has been energized.

It is also desirable that a means be provided for adjustably controllingthe rate of iiow through the rst valve to open. For this purpose, athrottling adjustment is provided which may be manually adjusted tocontrol the rate of ow through the port controlled by the valve i9. Tothis end,

a ange 49 is provided integrally with the parof the Bange to adjustablydecrease the openings of the V ports. The disk 5| is carried by a screw52 which in turn is adjustably carried by a packing nut 53 secured andsealed to the valve body as shown in Figure 1. The top of the nut 53 isprovided with a. pair of transverse slots 54 disposed at 90 degrees toeach other whereby the nut yieldably grips the screw 52 to-hold ity inan adjusted position. The upper ,end of the nut 53 is counterbored tofreely receive the nonthreaded end of the screw`52. AThe lower end ofthe nut 53 is further counter-bored and threaded to receive a nut 55 influid-tight relation. The

maximum adjustment of the throttling valve is determined by theengagement of the disk with the packing nut 53. In this position,clearance is provided between the screw 52 and the nut 55 which assuresthat the nut 55 will be tightly engaged with the nut 53. The minimumadjust-` ment of the throttling valve is determined by the engagement ofthe disk 5| with a snap ring 55 provided in the ange 49 as shown inFigure 1.

In case of power failure, it is desirable that one of the valves may bemanually operable to provide fluid ow. For this purpose, a packing nut51 is secured and sealed to the valve body |0 as shown in Figure 1.Extending through the nut 51 is an actuating pin 58 which carries atransverse pin 59 receivable in a' 'transverse slot 60 provided in theupper end of the nut 51. The lower end of the pin 58 carries a button6|, and between the button and the nut 51 a spring 62 is inserted. Aprotective guard 63 is secured to the nutA 51 and may be removed when itis desired to manually open the .valve 20. In opening the valve, the pin58 is moved upwardly into engagement with the valve by compressing thespring 52 until the pin 59 clears the top of the nut 51, after which aslight twist of the pin 58 moves the pin 59 out of the slot 60 to holdthe pin 58 in an actuated position.

The valve 9 further comprises a panel generally indicated by the numeral64. The panel 64 is carried by a plate 66, being secured theretobysuitable screws 65. The plate 66 in turn is secured to the casing 36by any suitable means such-as welding. An opening 61 is provided in thecasing 36 and plate 66 through which the The timing means for delayingthe opening of the valve 20 is mounted on the panel 54 and is generallydesignated by the numeral 11. The timing means 11 comprises a bimetallicelement 18 which is carried on one end by a bracket 19 of electricallyconductivematerial and is secured to the bracket by suitable screws 80.The other end of the element 18 carries a switch blade 8| which in turncarries a double faced contact 82; The contact 82 is engageable withspaced fixed contacts 83 and 84. The contact 83 is adjustably carried bya bracket 85 of electrically conductive material, and the contact 84 issimilarly carried by abracket 86 also formed of electrically conductivematerial. The terminal 15 is secured to the bracket 86. The bracket 86also carries a permanent magnet 81 which is secured thereto by plate lofelectrically conductive material whichv is secured to the underside ofthe panel 64 by a pivot 89. The terminal 1| is also carried by the plate90. The opposite end of the bracket 19 is secured to the plate 90 by aneccentric screw 9| which may be adjusted to vary the position of themovable contact 82 with respect to the fixed contacts 83 and 84.

- A heater 92 is mounted adjacent the element 18, being wound on acarrier 93 formed of any suitable material such as'mica. Additionalsheets 94,which also may be of mica, are disposed ,on each side of thecarrier 93 and secured together with the carrier 93 to the bracket 19 bymeans of the screws 80. One end of the heater 92 is connected to anupwardly extending projection of an electrically conductive plate 95which is secured to the underside of the panel 64 by the terminal screw10. The otherend 0f the heater is connected to the upwardly extendingend of an electrically conductive plate 96 which is securedto theunderside of the panel 64 by being connected to the bracket 85 by ascrew 91.

Also mounted on the carrier 93 is a resistor 98 which may be woundthereon as shown in Figures 2 and 3. One end of the resistor is suitablyconnected to the adjacent end of the heater. The other end of theresistor is provided with a terminal 99 which is secured under one ofthe screws 80 to ground the heater to the bracket 19.

The terminals 10, 1| and 14 additionally serve as binding posts forexternal wiring |00, |0| and |02, respectively, by means of which thevalve 9 may be connected into a valve control circuit.

' The wires |00, |0| and |02 are brought out through a nipple |03 whichis carried by the right angle portion |04 of the plate 66. The wires arefirst threaded through a washer |05 which is disposed between the panel64 and the nipple |03 in the manner shown. 'Ihis arrangement relievesthe connections between the wires and the terminals from stresses andstrains applied to the wires externally of the valve 9. The panel 64 andtiming means 11 are enclosed by a housing |06 which is bifurcated asshown at |01 to clear the nipple |03. The housing |06 is further held inplace by a screw |08 Awhich engages'the solenoid housing 36.

In Figure 4, the electrical connections between the several parts of thevalve 9 are shown sche matically in connection with a transformergenerally indicated by the numeral |09 and a twostage thermostatgenerally indicated by the numeral ||2.

The transformer |09 comprises a primary Winding I0 which may beconnected to a suitable source of A. C. power, and a secondary windingThe thermostat ||2 may be made responsive t a .temperature indicative ofa need for operation carried by the blade H4 engages va fixed contact`The terminal is connected to the contact H6 by the external`conductorI8I, the terminal 1I is connected to the lower side of the secondary I'II of the transformer by the external conductor |00, the terminal 14 isconnected to the fixed contact H8 by the external conductor I02, and a;conductor H9 is connected between the top side of the secondary III andthe bimetallic element H9.

e 8 v through the resistor thereby substantially reducing the currentnow. The current flow through the heater, however, is sufllcient tomalntain the contact 82 in engagement with the contact 84. `Thisreduction in current flow makes it possible to supply a large amount ofheat initially to obtain a short heating period, while thereafter fmaintaining the temperature low enough to give a short cooling period. Areduction in energization of the heater is further desirable inasmuch asit substantially reduces the temperature rise of the valve 9.

On the first rise in temperature, whereupon the blade III moves in thedirection of the legend Hf the contact H1 moves out of engagement withthe contact H8 to immediately deenergize the winding 30a, the valve 20then closing under In the operation of Figure 4, with the thermostatI'I2 in the position shown, the space is at the desired temperature.Upon a rst drop in temperature the movable contact H5. engages the fixedcontact H9 to establish a circuit for energizing the winding 90 andthe'heater 92. The circuit to the winding 30 may be traced as follows:from the top side of the secondary III through conductor II9, elementIII, blade III, contacts H5 and H9, conductor IOI, lead wire 68, winding30, lead wire 59 and conductor |00 back to secondary winding III. Uponenergization of the winding 30, the valve I9 is moved to an openposition providing a minimum rate of now to the furnace in accordancewith the ad` justment of the manual adjustingv means. The circuit to theheater may be traced as follows: from the top side of the secondary IIIthrough the conductor II9, element II3, blade IM, contacts H5 and H8,conductor IOI, conductor 95. heater 92, conductors 98, 85, contacts 83,82, element 18, and the resistor 98 and conductor 99 in parallel to theconductor 19, thence through the pivot 89,-conductor 90, and conductor|00` back to the secondary I I I. It should be pointed out that becauseof the shunt circuit in parallel with the resistor 98 that practicallyno current ilows through the resistor 98. Upon energization theinfluence of gravity and the Aspring means l heretoforedescribed. Asecond rise in temperature, causing further movement of the blade H4.

in the direction off legend H. causes the contact H5 to disengage thecontact H9, whereupon the winding 90 and heater 92 are immediately de-.energized The valve I9 then moves to its closed position under theinuenceV of gravity and its' spring means.

In some instances where `temperature rise of Y the valve and shorttiming periods are not a material operational consideration, theresistor 98 may be dispensed with. The connections for such anarrangement are shown in Figure 5. In

the circuit of Figurefthe heater 9211s provided with a terminal |29rsimilar to the terminal 99 secured to the resistor 98 and is similarlysecured to the plate 19. Also, `in Figure 5 the element 18 carries asingle faced contact I 2I rather than the double faced contact 92of-liisure 4. y

In the operation o! Figure 5, upon a first drop in temperature, thecontact H5 engages the contact H8 toestablish -a circuit-for energizingthe winding and theheater 92. The circuit to.v

the winding 99 may be traced as` follows: from thetop sideA of thesecondary `III through the conductor H9, element H3. blade III, contactsof the heater 92 a time period is initiated during which the element 18is under the influence of the heat generated by the heater 92. Upon a'continued drop in temperature causing further movement of the switchblade: I Il in the direction of the legend C the contact II1 engages thecontact II9.' If this occurs before the end of the time period, acircuit is completed to the Winding 30a upon movement of the elementcausing con- II'5 and H9, conductor I`0 I, lead wire 98, winding 30,lead wire 99, and conductor |00 back to secondary HI. Upon theenergization of winding 30, the valve I9 is moved to its open positionto provide a minimum rate of fluid flow. The circuit for energizing theheater 92 may be traced as follows: from the top side of secondary III'lthrough conductor I|9, element II'3, blade III, contacts H5 and H8,conductor IOI, conductor 95, heater 92, terminal |20, conductor 19,contact 82 to engage contact 84 with a snap action.

contact 92 with the contact 94, Ithe contact 82- disengages the contact83, whereupon the circuit for shunting the resistor 981 is broken andthecurrent through the heater -is forced to ilow ductor 90, and conductorI00 back to the secondary winding I I I. Upon the energization of theheater 92, a time period is initiated at the end of which thek element18 moves to cause contact I2I to engage the contact 8lwitha snap action.If during the time period the temperature has continued to drop, thecontact H1 will have moved4 into engagement with the contact II8 beforethe close of the period. In such case, upon engagement of the contactI2i with the contact 81, a circuit is established for energizing the'winding 90a. This circuit may be traced as follows: from the top sideof secondary III through the conductor II9, element H3, switch bladeIll, contacts H1, H8, conductor |02, lead wire 12, winding 30a, leadwire 13, conductor 88, contacts 84, I2I,.element 1,8, conductor 19,conductor 9Il,l and conductor |00 back to secondary III. Uponenergi'zation ofthe winding 90a, the valve 20 is moved to its openposition, thereby providing maximum fluid flow to the furnace.

As in the case of the circuit of Figure 4, upon aV first rise intemperature the contacts ||1 and |'|8 disengage to immediatelyldeenergize the winding 30a and thereby cause the valve 20 to which thevalve connections are substantially the In the operation of Figure 6,upon-a first drop` in temperature the blade |'|l moves inthe directionof thel legend C causingv engagement of the contact |25 with the contact|26 to establishv a circuit for energizing the winding 30 and the heater92. This circuit may be traced as follows:

from the top side of the secondary through the conductor ||9, elementIIS, blade ii'l, contacts |25, |26, conductor to the terminal 10, thencein parallel throughv the lead wire 08, winding 90, lead wire 99, to theterminal 1|, and through the conductor 95, heater 92, conductor 96,conductor 85, contacts 83 and 82, element 18, conductor 19, andconductor 90 to the terminal 1|', thence through conductor |00 back tosecondary ||i. Upon energization of the winding 30 the valve |9 is movedto its open position providing minimum fiuidow to the furnace. Uponenergization of the heater 92 a time period is initiated after which thecontact 02 disengages the contact 83 and engages the contact 8l with asnap action. As described in connection with Figure 4, upondisengagement of the contacts 82 and 83, the circuit shunting theresistor 98 is broken and the current to the heater is forced to flowthrough the resistor -98, thereby substantially reducing energization ofthe heater. Upon engagement of the contact 82 with the contact 8l, acircuit is established for energizing the winding 30a. This circuit maybe traced as follows: from the top side of secondary through theconductor H9, element lf3, blade IM, contacts |25, |26, conductor |0i,lead wire 12, winding 30a, lead wire 13, conductor 86, contacts 0l. 82,element 18, conductor 19, conductor 90, and conductor 00 back -tosecondary Energization of the winding 30a causes the valve 20 to movetoits open position thereby providing maximum fluid flow to the furnace.

Upon a first rise in temperature the switch From the foregoing, it hasbeen seen how in each of the circuits of Figures 4 through 6 theactuating. windings 30 and 30a and theheater 92 are connected inparallel across a common source of power, and how the timing means 11has been connected to.delay the energization'of the winding 30a in eachcase. Ithas also been seen that with a few simple changes these resultsmay 1o be obtained whether the valve be operated in a single ortwo-stage circuit.`

From the foregoing it is now obvious that 1 v have provided a valvestructure which is Well adaptable to fulfill the. objects of theinvention set forth hereinabove. While I have disclosed but a single'structural embodiment-of the valve, it is obvious that furtherembodiments and ,structural modications thereof may be, made.Accordingly, I contemplate all such changes as would naturally occur tothose skilled in the art without departing from the spirit of theinvention as deiined by the appended claims.

I claim as my invention:

l. In a condition control system, in combination, a step-openingelectric valve for supplying a fluid fuel to a burner at minimum andmaxivmum rates of flow comprising a pair of valves,

an actuating winding for each valve operable to move the same betweenclosed and open posi-- tions when energized, and an electric timeswitchhaving'an electric heater therein associated with the windings forproviding a time delay between the energization of the windings, meansresponsive to a condition indicative of a need for operation of theburner for concurrently initiating the energization of one of thewindings and said time switch to open one of said valves therebyproviding a minimum rate of flow of the fuel, said time, switchinitiating a time period and being operable at the end of the period toconcurrently reduce the flow of 4energizing current to said electricheaterA and energize the other of the windings to open the other of saidvalves to provide a miximum rate of ow.

2. In a condition control system, in combination, a pair of electricallyoperable valves for controlling the iiow of a fluid fuel to a burner,

said valvesl being operable to move from closed to open position whenenergized, an electric time switch concurrently energizable with a firstof said valves and operable to delay the'energization of the other valvefora time period, a means responsive toa condition indicativeof a needfor operation of the burner, a first switch means operable by saidlatter means in response thereof to a certain condition value forenergizing said first valve and time switch, a second switch meansoperable by said latter means in response thereof to a differentcondition value and operable to energizev said second valve after saidtime period, means controlled by said time switch for 4 reducing theflow ofenergizing current to said electric time switch concurrently withthe energization of'said second valve, and means cooperating with saidpartly deenergized time switch for maintaining said second valveenergized.

3. In'a condition control system, in combination, a pair of electricallyoperable valves for controlling the now of a uid fuel to a burner. saidvalves being operable to move from closed to open position whenenergized, an electric time switch concurrently energizable with a firstof said valves and operable to delay the energization of the other valvefor a time period, a means responsive to a condition indicative of aneed for` operation of the burner, a pair of switch means operable insequence by said latter means in response thereof to successive changesinthe value of the condition, a first of said swit"ch means completing acircuit for concurrently energizing said first valve and said timeswitch, and thereby initiating saidtime period, said second switch meansbeing arranged in series in a circuit with said time switch and saidsecond valve whereby the energization of the second valve is delayedwhen both said switch means are closed within said time period and saidsecond valve opens immediately when said second switch means closesafter said time period, and magnetic means operable to assist saidelectric time switch energize said second valve.

4. In a condition control system, in combination, electrical valveapparatus for supplying a iluid fuel to the burner of a conditionchanger at different rates of i'low comprising a plurality of valves, anactuating winding for each valve operable to move the same betweenclosed and open positions when energized, and a thermal time switchhaving a heater associated with the windings for providing a delayedopening of at least one of said valves, a source of power, meansresponsive to a condition indicative of a need 'for operation of saidcondition changer, and

electrical connections between the source of power, condition responsivemeans, and apparatus, said connections providing a first circut forconcurrently energizing said switch and at least one of said windingswhen said condition responsive means responds to a predetermined valueof the condition thereby opening at least one valve to provide a rstrate of fluid flow, said time switch concurrently initiating a timeperiod, said switch being operable at the end of said time period tosimultaneously cause a reduction in the supply of operating energy tosaid heater and the establishment of a second circuit for energizing thewinding of said delayed valve to open the same thereby providing anincreased fluid i'loW.

5. I n an electric valve control apparatus, a valve housing having aninlet and an outlet, a pair of valves positioned in said housingintermediate said inlet and outlet and adapted to normally assume aclosed position, electrical motive means for each valve, said motivemeans being operable when energized to move said valves to openposition, electrical timing means so connected as to be energizablesimultaneously with one of said motive means, means controlled by saidtiming means and operative to cause energizatlon of the other of saidmotive means only after a time period during which said timing means isenergized, and means for reducing the energization of said timing meansto a fraction of its iirst energization concurrently with theenergization of the electrical motive means of said other valve.

6. In an electrical valve control apparatus, a housing having an inletand an outlet, a pair of normally closed valves positioned in parallelarrangement in said housing intermediate said inlet and said outlet,,electrical motive means for each valve, said motive means beingoperable when energized for moving said valves to open position,electrical timing means having a heater energizable concurrently withone of said motive means, means operable concurrently with theenergization of the other of said motive means f or partially reducingthe flow of energizing current to said heater, and means cooperatingwith said partly deenergized heater for maintaining said other motivemeans energized.

7. In an electrical control apparatus, a pair of normally closed valves,electrical motive means for each valve, said motive means being operablewhen energized to move and maintain said valves in open position,electrical timing means having an electric heater arranged in a parallelcircuit and energizable concurrently with a rst of said motive means toinitiate a time delay between the energization of the rst and second ofsaid motive means, means for positioning a resistance in said parallelcircuit to partially reduce the ilow of energizing current to saidheater concurrently with the energizeation of a second of said motivemeans, and means for removing the resistance from said parallel circuitupon deenergization of said second motive means.

8. In an electrical valve control apparatus, a pair of normally closedvalves, a pair of electrically actuated means for causing said valves tomove from closed to open position, and means for interposing a timedelay between the opening movement of a first of said valves and asecond of said valves, said last means comprising a thermoelectricdevice arranged in parallel with said electrically actuated means andoperable to initiate a timing period upon energization of one of saidelectrically actuated means for operating a first of said pair of valvesand to cause the energization of said electrically actuated meansv foroperating the second of -said pair of valves upon .the termination ofsaid time period, and means actuated by said thermoelectric deviceforpartially reducing the iiow of energizing current to said heater uponthe energization of said electrically actuated means for operating saidsecond valve.

MARVIN R. LAING.

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